SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09fce0afecaa3ca190ee28098503bce375e3b0df22f2ce3f759030bcba7a050f' 
  AND token = 'l05spR8tcvEsK6NFfzOcWmXe4cgOqPJHrkLBrUBY4Iw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}